How to find out distribution's mode?

For 1c) It asks to give the distribution's mode. Well I never recall learning that anywhere on the book. How would I figure out what is the mode of it?
I figured out the table as soon below:
P(0) = 2.016e-8
P(1) = 9.8428e-7
P(2) = 0.000021625
P(3) = 0.00028155
P(4) = 0.0024056
P(5) = 0.014094
P(6) = 0.057343
P(7) = 0.15998
P(8) = 0.29291
P(9) = 0.3178
P(10) = 0.15516
But nowhere does any of those numbers match up to one another to be called a mode. So this has gotten me really confused.

*For 1B) Is the answer All real numbers?
*For 1D) Is the answer P(9) = 0.3178?

For 1c) It asks to give the distribution's mode. Well I never recall learning that anywhere on the book. How would I figure out what is the mode of it?
I figured out the table as soon below:
P(0) = 2.016e-8
P(1) = 9.8428e-7
P(2) = 0.000021625
P(3) = 0.00028155
P(4) = 0.0024056
P(5) = 0.014094
P(6) = 0.057343
P(7) = 0.15998
P(8) = 0.29291
P(9) = 0.3178
P(10) = 0.15516
But nowhere does any of those numbers match up to one another to be called a mode. So this has gotten me really confused.